This application claims the priority benefit of Taiwan application serial no. 88105360, filed Apr. 3, 1999, the full disclosure of which is incorporated herein by reference.
1. Field of Invention
The present invention relates to a shutter door opener. More particularly, the present invention relates to an opener for opening the shutter door of a disk cartridge.
2. Description of Related Art
At present, most laser disk reading machines such as DVDs or CDs can accept either bare laser disks or laser disks that are enclosed within a protective cartridge. The cartridge is able to prevent dust deposition, scratches, air moisture or unwanted illumination. However, when a disk cartridge is pushed into a laser machine, a suitable opener must be present to open the shutter door on the cartridge so that laser beam can shine onto the laser disk for performing a data-read operation. FIGS. 1A and 1B illustrate one type of conventional shutter door opener for the cartridge, and FIGS. 2A and 2B illustrate a second type of conventional shutter door opener. In general, the mechanisms of most conventional shutter door openers suffer the drawback of having too much resistance or friction. Therefore, the shutter doors are difficult to open. Furthermore, even if the internal friction is only moderate, too many components may be required making assembling very difficult. In addition, the assembled system may be so large that too much space is required to accommodate the system.
FIGS. 1A and 1B are two top views showing the opening of the shutter door of a disk cartridge using a first type of conventional opener design. The shutter door opener includes an opener beam 22 on a base metal plate 20. Two sliding slots 24 and 28 are formed in the base metal plate 20. One of the slots 24 serves as guide for the head section A of the opener beam 22 to sweep out an arc. The other slot 28 permits a latch pin attached to the opener beam 22 to sweep out an arc. Furthermore, the shutter door opener includes an extension spring 26. One end 26A of the spring 26 is hooked onto the latch pin of the opener beam 22, whereas the other end 26B is fixed onto the base metal plate 20. The opener beam 22 is able to turn relative to a rotating axis 30. In fact, one end of the opener beam 22 is fixed by a pin insert anchored to the rotating axis 30 so that the other end of the opener beam 22 is capable of moving along the slot 24. As shown in FIG. 1A, just before a disk cartridge 10 is pushed into a laser machine, the shutter door 12 on the cartridge remains closed. When the disk cartridge is pushed into the laser machine, point B on the shutter door 12 first contacts the head section A of the opener beam 22. Thereafter, when the cartridge is pushed in a little further, the head section A of the opener beam 22 sliding along slot 24 gradually drives the shutter door 12 to the left. In the meantime, the spring 26 having one end 26A hooked to the opener beam 22 be carried along in the direction of the slot 28. Finally, the shutter door 12 is fully opened as shown in FIG. 1B. Once the spring 26 is fully extended, a restorative force is provided. Therefore, as the disk cartridge 10 is drawn out, the opener beam 22 can return to its former position as shown in FIG. 1A. In the aforementioned design, the shutter door is opened using the movement of the opener beam 22 along a small radial arc. In other words, the opener beam 22 has only one degree of freedom. To prevent the cartridge from being stuck inside the laser machine, the opener beam 22 must have a considerable length. Hence, extra room for accommodating the wide sweep of the opener beam 22 must be set aside, which is quite demanding for a laser machine having limited internal space.
FIGS. 2A and 2B are two top views showing the opening of the shutter door of a disk cartridge using a second type of conventional opener design. The shutter door opener is very similar to the one in FIGS. 1A and 1B except that one end of the opener beam 22xe2x80x2 is not fixed to the base metal plate 20. Instead, a sliding slot 30xe2x80x2 is formed for the end section of the opener beam 22xe2x80x2 to slide along. In this design, a pin is attached to the respective front section and the end section of the opener beam 22xe2x80x2. Hence, the entire opener beam 22xe2x80x2 is capable of sliding along slots 24xe2x80x2 and 30xe2x80x2 in the process of opening the shutter door 12. In fact, the two slots 24xe2x80x2 and 30xe2x80x2 serves as end constraints for the opener beam 22xe2x80x2 so that a set track is followed by the opener beam 22xe2x80x2. However, this type of design requires detailed calculations for relative positioning of the two slots 24xe2x80x2 and 30xe2x80x2. Otherwise, the opener may be jammed in the middle so that the shutter door 12 is not fully opened. Moreover, this type of opener produces greater friction, too.
In conclusion, the first type of conventional door opener tends to occupy too much space, and the second type has such complex moving parts that the cartridge door may be jammed.
In light of the foregoing, there is a need to produce a better door opener for opening the shutter door of a disk cartridge.
Accordingly, the present invention is to provide a shutter door opener for opening the shutter door of a disk cartridge such that the sliding area demanded by the opener beam is reduced. Hence, the shutter door opener does not occupy too much room. Furthermore, the degree of opening of the shutter door can be controlled by tailoring the curvature and profile of the sliding slots, unlike the fixed arc trajectory utilized by a conventional opener beam.
Another aspect of this invention is to provide a shutter door opener having the same door-opening capacity as a conventional unit for opening the shutter door of a disk cartridge, but with fewer components. Hence, the shutter door opener can be assembled quickly and production cost can be reduced.
To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention provides a shutter door opener for opening the shutter door of a disk cartridge. The shutter door opener is generally installed inside a laser disk reader on a chucking plate. The shutter door opener for opening the shutter door of a disk cartridge comprises a door-opening component. The door-opening component includes an opener beam and a slot on the opener beam for sliding the opener beam. The opener beam further includes a slider at the head section of the opener beam, and a pin that passes through a slot of the opener beam and fastened to the chucking plate. Hence, the opener beam is free to move relative to the fixed pin and is only constrained by the slot. There is a first slot in the chucking plate. The first slot is designed in such a way that the slider at the head section of the opener beam is able to latch onto and slides freely along the slot. The opener further includes an extensible element with one end fixed onto the chucking plate while the other end is fixed onto a hook attached to the mid-section of the opener beam. The opener also has a second slot on the chucking plate. The second slot allows the hook on the opener beam freely slide along.
In a second embodiment, the invention provides a shutter door opener for opening the shutter door of a disk cartridge. The shutter door opener is installed on a chucking plate. A first pin insert and a second pin insert are fixed to the chucking plate. The shutter door opener includes an opener beam, a slot beam, a connecting beam and an extensible element. The opener beam has a first end and a second end. The first end of the opener beam is coupled to the first fixed pin insert so that the opener beam is capable of rotating about the first pin. The slot beam has two ends and a slot along the mid-line section. The second fixed pin insert passes through the slot of the slot beam so that the slot beam is able to move past the second pin insert guided by the slot. One end of the slot beam is coupled to a section between the first and the second end of the opener beam, and the other end of the slot beam is coupled to one end of the connecting beam. Besides joining to the slot beam, the other end of the connecting beam is coupled to the first end of the opener beam. One end of the extensible element is fastened onto the opener beam near its mid-section while the other end is fastened to the chucking plate.
As a disk cartridge is placed into a laser disk reader, the second end of the opener beam first touches the shutter door. The opener beam then rotates about the first pin. At the same time, the slot beam is also capable of sliding past the second pin. Consequently, the shutter door of the disk cartridge is opened by the opener beam.
In a third embodiment, the invention provides a shutter door opener for opening the shutter door of a disk cartridge. The shutter door opener is installed on a chucking plate. A first pin insert and a second pin insert are fixed to the chucking plate. The shutter door opener includes an opener beam, a slot beam and an extensible element. The opener beam has a first end, a second end and a first slot. The first pin passes through the first slot in the opener beam so that the opener beam is capable of sliding past the first pin. The slot beam also has a first end, a second end and a second slot. The second pin passes through the second slot of the slot beam so that the slot beam is also capable of sliding past the second pin. The second end of the slot beam is coupled to the beam opener somewhere between its first and the second end. One end of the extensible element is fastened onto the opener beam near its mid-section while the other end is fastened to the chucking plate.
As a disk cartridge is put into a laser disk reader, the second end of the opener beam first touches the shutter door. The opener beam, guided by the first slot, turns and slides relative to the first pin. Concurrently, the slot beam, guided by the second slot, also slides relative to the second pin. Consequently, the shutter door of the disk cartridge is opened by the opener beam.
In this invention, the opener beam of the shutter door opener is capable of horizontal movement as well as rotation at the same time. Since area swept out by the opener beam is smaller, less space is needed to accommodate the shutter door opener inside a laser disk reader.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed.